Division mechanism for key-respon



Dec. Z7. 1949 J. M. I AlHo DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet 2 mj NN l... v/fi. mmm

Il Il l Dec. 27, 1949 J. M. LAIH 2,492,703

DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 12 Sheets-Sheet 5 J. M. I AlHo 2,492,703 DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES 12 Sheets-Sheet 4 Dec. 27, 1949 Flled Aug 8, 1942 De@ 27, 'N49 J. M. LMHO 2942;?@3

DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Dec. 27, 1949 J. M. LAlHo 2,492,703

` DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. a, 1942 12 sheets-sheet e 2 3&5 303 322 22 @y g, of

J. M. LAM-:o JAVQZQS DIVISION MEGHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed. Aug. s, 1942 12 sheets-shew 7 ATTORNEY @me E949 J. M. LNH@ LZZQ DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet 8 INVENTOR Umef? M Lan/0 ATTORN EY De@ 27, i949 J. M. LAYHO DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet 9 ATTORNEY J. M. LAHHO DIVISION MECHANISM FOR KEY-RESPONSIVE Bem 27, N49

CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet l0 @www @www Www.

Dec. 27, 1949 J, M. LALHO 2,492,705#

DIVISION MECHANISM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet l1 INVENTOR @my Mza/z@ ATTORNEY Der:o 27, 1949 J M LAM-io DIVISION MECHNIM FOR KEY-RESPONSIVE CALCULATING MACHINES Filed Aug. 8, 1942 l2 Sheets-Sheet l2 INVENTOR @5 www M 13m/w BY )EMM .0@ @www ATTORNEY Patented Dec. 27, 1949 DIVISION MECHANISM FOR KEY-RESPON- SIVE CALCULATING MACHINES Jalmer M. Laiho, Skokie, Ill., assignor to Felt & Tarrant Manufacturing Company, Chicago, Ill., a corporation of Illinois Application August 8, 1942, Serial No. 454,111 12 claims. (Cl. ass-s2) This invention relates in general to calculating machines and has more particular reference to the provision of means for facilitating the use of power-driven, key-responsive machines in negative forms of calculation; namely, subtraction and division.

A principal object of the invention is to simplify division operations in and with key-responsive calculating machines.

Another important object of the invention is the provision of control means operable to cause the complemental values of a divisor to be automatically entered into the accumulator in division operations.

A further important object of the invention is to eliminate the complemental indicia, employed for the purpose of performing division operations, on the ordinal keys of key-driven or key-responsive calculating machines having uni-directional accumulator mechanism. I

Another object of the invention is the provision of means for causing the automatic entry into the accumulator of 9s in all denominational orders where no keys are depressed to the right of the leftmost o1' highest order of the divisor, except -the units order, in which 10 is added if no key is depressed therein.

Another object of the invention is to dispense with the necessity of depressing keys corresponding to the value of one less than the actual value of the divisor when the keys are simultaneously depressed in performing division problems on a key-driven or key-responsive calculating machine.

A further important object of the invention is the provision of means to allow the depression of keys representing the actual values of the figures of the divisor when performing division problems on a key-driven or key-responsive calculating machine.

Another important object of the invention is to provide a key-responsive calculating machine wherein the same digit key is depressed for the corresponding digit value regardless of whether division or any other type of calculation is being performed on the machine.

Another object of the invention is to eliminate the necessity in a key-driven or key-responsive calculating machine, as heretofore, of depressing a value key when a cipher occurs between two figures of value in the divisor.

A further object of the invention is to eliminate the necessity in a key-driven or key-responsive calculating machine for ignoring the figure 9 i 2 l when it occurs in the divisor between two figures of value.

A further object of the invention is the provision of means in a key-responsive calculating machine for releasing keys depressed in entering the subtrahend which have been retained in depressed position preparatory to a subtractive operation.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

In the drawings;

Figure 1 is a top plan view of a calculating machine embodying my invention, showing the minus and equals keys and the division key located to the'left of the several denominational orders of digital keys;

Figure 1A is a top plan View of a single denominational order of keys complementally marked in accordance with the former method of performing negative calculation with key-driven or key-responsive calculating machines;

Figure 2 is a longitudinal vertical section taken through the calculating machine shown in Fig. 1 on a plane-adjacent a column of digital keys;

Figure 3 is a longitudinal vertical section taken through the calculating machine of Fig. 1, on a plane adjacent the overflow column and showing the digital control shifting mechanism and details of the accumulator mechanism;

Figure 4 is a longitudinal vertical section also taken at the left side of the calculating machine shown in Fig. l, and showing the subtraction and division control mechanism;

Figures 5, 6 and '7 are detail Views of the digital actuation control mechanism;

Figure 8 is a detail view showing the construction of the digital control bar, taken along the line 8-8 of Fig. 6;

Figure 9 is a transverse section taken at the rear of the machine and looking toward the front thereof, with certain parts omitted to show details of the division control mechanism when the machine is set for additive actuation;

Figure 10 is a similar view showing the division control mechanism when the machine is set for divisive operation;

Figure 11 is a top plan view, broken away centrally from front to back, of the calculating "machine shown in Fig. 1, showing details of the Figure 12 is a perspective view of the overlapping means for causing automatic actuation of all denominational orders where no keys are depressed to the right of the key representing the leftmost or highest order gure of the divisor which is depressed in entering the divisor during a divisive operation;

Figure 13 is a top plan view of the latch means for preventing relatching of the power trip mechanism and digit control keys in depressed position after a po-wer action has taken place;

Figure 14 is a perspective view of the said latch;

Figure 15 is a longitudinal vertical section of the calculating machine shown in Fig. 1 taken at the right side of the machine andshowing the release keys and zeroizing crank;

Figure 16 is an enlarged view-showing details of part of the interlocking mechanism;

Figure 17 is a front elevation of the mechanism. shown in Fig. 16 taken on the line I'l-I'l of Fig. 16;

Figure 18 is an enlarged view showing some parts of the mechanism of Fig. 16 in changed position, and with parts broken away;

Figure 19 is a View showing a supplemental key release mechanism;

Figure 20 is a perspective View of a modification of the supplemental key release mechanism employed. in a single order of the machine, in order to clear certain parts which obstruct and prevent the use of the key-release mechanism of Fig. 19 in that order;

Figure 21 is a side elevation of part of the interlocking mechanism associated with the control keys at the leit hand side of the machine;

Figure 22 is a rear view of the mechanism shown in Fig. 21 taken on the line 22-22 of Fig. 21 and drawn at a diiferent scale;

Figure 23 is a front View of the mechanism shown in Fig. 21 taken on the line 23--23 of Fig. 21.

For the purpose of illustrating my invention, I have shown in the drawings a key-responsive, power-driven calculating machine similar to that shown and described in Patent No. 2,063,964@ issued December l5, 1936, with some changes as subsequently shown in United States Letters Patent No. 2,018,933, issued October 29, 1935, and with improvements illustrated, described, and claimed in my co-pending application, Serial No. 411,194, filed September 17, 1941, and issued Novemoer 12, 1946, as United States Letters Patent No. 2,410,823. Referring more particularly to the drawings, the calculating machine is shown as having an outer casing v2l within which the various instrumentalities of the machine are mounted on skeleton frame members or partition plates 22 disposed between the actuating mechanisms of the Several denominational orders and Secured together in spaced relationship at suitable points by tie-rods 23. A plurality of columns of digital keys 24, normally held in raised position by means of springs 38, are arranged to extend through a keyboard 25, positioned as part of the upper wall of the casing 2l, which keys are adapted for manipulation to determine the digital degree of actuation to be imparted to the different denominational orders of accumulator mechanism. Each column of keys 24 controls the rotation of an accumulator actuating pinion 26 (Fig. 3) journaled upon a transverse shaft 21 that extends across thevmachine and is Supported by the frame members .22. Rotation of each of the actuating pinions 26 is transmitted throughL an internal ratchet mechanism to a combined lantern wheel and accumulator gear 28 (Fig. 3) which is also journaled on the shaft 21. The gear of each of the lantern wheels 28 meshes with a carrying gear 30 journaled on a shaft 29 (Fig. 3), which is disposed in parallel relationship to the shaft 2i. The carrying gears also respectively mesh with intermediate gears 3I journaled on a transverse shaft 32, each of which in turn meshes with a numeral wheel pinion 33 journaled on a transverse shaft 3H and xed to a numeral wheel 35 (Fig. 3).

Carrying mechanism is provided in each denominational order of the accumulator mechanisrn for the purpose of impartng a digital unit of actuation thereto each time that a tens transfer is to take place from the next lower denominational order of the accumulator. This mechanism, as well as that hereinbefore described, is more fully disclosed in United States Letters Patent No. 1,357,747, and No. 1,357,748, issued on November 2, 1920, and includes a carrying-cam member 36 (Fig. 3), which is given a 180 rotation by a suitable carrying motor spring 3i associated with a carrying gear of the next lower denominational order for each tens transfer that is to be effected. 'Lhe carrying-cam member 38 -acts upon a dolly roll secured to a bell-crank carryinglever (not shown) to swing the latter in a clockwise direction, viewing Fig. 3. Such swinging of Ithe carrying-lever causes a carrying pawi 4i pivotally mounted on said lever to throw the lantern wheel and accumulator gear 28 a sufiiclent distance to impart, through the train of gears, a `ital unit of actuation to the numeral 111e adding is accomplished upon depression oi' the keys Eil and correspcncing actuation of gear sectors l2 (Fig. 3) which are in mesh with the pinions 2S, a said sector being associated with each dencminatonal section of the accumulator unit in association vv ith its controllng column of keys. The gear sectors and the control and actuating mechanism for them are duplicated for each denominational order of the calcu.ating machine, and a general description of a single set of such mechanism will be sufficlent for an understanding of them all, except that they have to be arranged and adapted to cooperate selectively and collectively with the pov/er members.

The gear sectors i2 are mounted upon a shaft '43 which extends through the partition plates 22 of the machine, and are adapted to be moved downwardly (viewing Figs. 2, 3 and 4) on an idle or setting stroke in amount determined by the value of the particular digital key 2li of the assocated column depressed, this amount increasing in graduating steps from i to "9. The keys 2li in addition act through a power trip mechanisin to effect a connection whereby power supplied by an electric motor, indicated generally at M (Fig. 3), through a power shaft 45, which is connected to the motor in any suitable manner, is effective to extend a spring 13 associated with the particular order of mechanism with which the key depressed is indentied. Release of this spring thereafter accomplishes adding movement in amount determined by the particular digital key of the order depressed. Upon depression of said key, the gear sector 42 is moved through its idlev or downward stroke by the power shaft 45 into positionv to impart proper and accurate digital accumulation to the adding mechanism upon its return movement, which is accomplished by the associated spring 46.

,In the calculating machine shown in the draw- .,ings, depression of a key 24 causes its stem 41 `(Fig. 2) to engage a parallel motion bar 48 which Yis pivoted at the front at 49 and at the rear at 5I to levers 52 and 53, respectively, which levers -are pivoted in turn upon cross shafts or rods 54 and 54 extending 'through the partition plates 22. A link 55 is pivotally connected at 56 to the lever 52 and at 51 to the lever 53. The bar 48, levers 52 and 53 and the link 55 form part of a parallel `motion device, and are constructed and mounted as shown and described in United States Letters Patent No. 2,063,962, earlier mentioned.

Further .and more particular description of these parts is therefore thought to be unnecessary. Each of the gear sectors 42, as stated above, is pivoted upon the cross shaft 43, and through a yielding clutch 63 is articulately connected to a hook 58 by a link 56 (the hook 58 and link 59 being articulately connected to a vertical guide member 6B which in turn is pivotally mounted on a. shaft 56). Each gear sector 42 is also articuvlately connected to a movement controlling bar, generally shown at 6I, by a pin 62 securely xed to an arm 36 of the gear sector 42 (Fig. 3), as Will be later described in detail. A spring 64 attached to lever 53 and to a tail piece 65 of a latch member 66 carried by the bar 55 normally contributes toward holding the parallel motion device in elevated position for a purpose which will be presently explained. A dog 61 which is pivoted at 68 on the parallel motion bar 48 is provided with a laterally and downwardly extending lug 69, which is adapted for engagement with a. lug or shelf 1l on a spring-lifted lever 12 pivotally mounted on the guide member 68 with the hook 5 8. The operation of the parts is such that upon depression of a key 24, the stem 41 engages and depresses bar 48, imparting motion to the parallel motion device, which carries dog 61 downwardly to depress lever 12. A spring mounted on the pivot between the link 59 and the hook 58 engages the lever 12 and the hook to urge the rear end of the latter downwardly, so that it will normally cause engagement of the hook 58 with a toothed wheel 13 upon depression of lever 12. However, this spring connection between hook 58 and lever 12 will permit movement of the latter by the dog 61 relative to the hook, if the hook is restrained in its normal raised position of Figs. 2 and 4 in a manner to be later described. The toothed wheel 13 is fastened to the power shaft 45, which continually turns in a counter-clockwise direction. The engagement of the hook 58 with the Wheel 13 pulls the link 59 toward the rear of the machine, or toward the left, viewing Figs. 2 and 3, which imparts downward motion to gear sector 42, through the yielding clutch 63. Forward motion is thus imparted to the digital control bar 6I, until one of several lugs projecting vertically therefrom, as will be hereafter more fully explained, is stopped by the stem 41 of the key7 24 depressed.

The rearward motion of hook 58 and link 59, which are articulately connected to each other and to guide arm 66, causes said guide arm to pivot in a counter-clockwise direction about its shaft 50 to extend spring 46, one end of which is connected to the guide arm and the other end to avshaft or rod extending through partition plates 22. y The link 59 moves the gear sector 42 downwardly on an idle stroke and into position to imhook 58 and contraction of the spring 46. The downward movement of the gear sector 42 is under the control of the digital control bar 6l (Fig. 3), and the gear sector is halted when it has been moved downwardly the proper distance, enablingit upon return to impart the degree of digital advancement to the adding mechanism which corresponds to the particular key depressed. The yielding clutch 63 permits the continuation of the rearward movement of the link 59 after downward movement of the gear sector 42 has been stopped, and until the end of the power stroke and the automatic release of the hook 58. The release of the hook 58 is accomplished automatically in each instance, after a set increment of action has been imparted to the link 59, by the teeth of the wheel 13. Upon the return stroke (the operative stroke of the gear sector), the yielding clutch 63 permits relative movement of the parts in reverse direction to the beginning of the adding movement, and thereafter the adding actuation is accomplished.

It is apparent, therefore, that upon depression of a key 24, the digital control bar 6I determines the degree and extent of the downward movement of the gear sector 42, and the bar 48 accomplishes connection of the latter to the power mechanism. Means are provided to prevent return movement of the dog 61 before the hook 58 has opportunity to fully engage the toothed wheel, which means comprise latch member 66 which is pivoted at 14 on link 55. This latch member has an engaging arm 15 which is adapted to engage upon the laterally projecting end 16 of the dog 61 to hold the dog down against return upward movement and the parallel motion device in depressed position. Just prior to the release of the hook 58, a pin 11 in an upwardly extending arm 18 of vertical guide member 68 which, through its connection with hook 58 has been carried rearwardly, engages a linger 19 of latch 66 and frees the dog 61 so that the parallel motion device may return to normal raised position. However, if a digit key is held prolongedly in depressed position thereby preventing the rising of parallel motion bar 48 and dog 61, then means must be provided to assure the continued disengagement of latch 66 and dog 61. Upon the return or forward motion of hook 58, the horizontal shelf 1| of lever 12 engages the lug 69 of dog 61 to rock the dog counterclockwise to prevent the re-engagement of arm 15 of latch 66 with lug 16 of dosr 61 so that upon subsequent release of the digit key all the parts can return to normal position. A bar 8| having rearwardly extending pointed locking lugs or teeth 82, is pivoted upon studs 83 and 83 extending through slots 84 and 84 in bars 48 in each denominational order of the machine, said studs 83 and 83 being secured to bracket levers 52 and 53 respectively. Consequently, upon depression of a key 24, bar 8| is moved rearwardly (to the left viewing Fig. 2), relative to key stems 41. Referring, more particularly to Figs. 9 and 10, each key stem is provided adjacent its lower end with an aperture 85 extending therethrough into which the tooth 82 enters in the rearward movement of the bar 8l, thus holding the key down until the parallel motion device is released and the parts returned to normal elevated position. It will be understood that, while no two keys 24 of the same column or denominational order may be operated simultaneously, as described in Patent No. 2,043,- 021 issued June 2, 1936, any key of one order may be operated at the same time as any desired key part an ,adding movement upon release of the of any other denominational order or orders.

aisance In thev machine' in whichv `the 'presenti-invention is embodied; subtraction' is per-formed in" accordance with the method and means fully described in the aforementioned cpendingv applieation,` Serial No. 411,194, issuedNovember 12, 1946, as United States Patent No.' 2,410,823. A subtraction control device-is'providedwhich comprises a set of keys including minus 'and "equals control keys 8G and 8l.' respectively, located to thev left of the ordinal seriesof keys 24.

Referring to Fig. 4, the lower portion of the stem 88 of minus key 3o is in engagementwith a parallel motion bar 89 whichis a modied form of the parallel motion-bars 38 earlier described. Depression ol? the minus control key 6 and parallel motion bar Se causes forward movement (to the right viewing Fig. 4) of a link and allows latch member 256 to engage a dog to hold the parallel motion bar in depressed position; The key 86 is also maintained in depression position by a tooth SI formed on a bar e2 which is moved rearwardly upon depression of key 8e, allowing tooth el' toenter an aperture 25e inthe key stem 88. Subsequent to depression of the minus control 'key'eli the keys representing the-'subtrahend are depressed and maintained in such depressed position until the equals controlk'eylis depressed whereupon the-adding actuation which was not immediately responsive to depressionY ofY the digit lkeysis allowed to takeplace and Vthe-keys returned to normal elevated position.v `Upon depression of the minus control key Se, its-stem'e engages an upwardly extending' arm Sfl '4) of a lever 95 which is also provided with a" downwardly and forwardly extending varml 9S and ispivoted at 9'! on a pin iiXed to-'an 'intermediate plate .22. 'To the lower end'of the-lever Q5 is pivote'd apawl S8 which is'provicledl with a downwardly extending arm 9e, -a rearwardly extendingl horizontala'rm lill, and an* upwardlyextending arm I02.` 'The lower-arm S9 is normally positioned ailoove'a pin 1&5 in an arm 'lee which is securely'iast'ened to a transverse rock shaft lill'. Securely fastened to the shaft le? are lock arms |08 (Figsfz arid`3), one foreachdenominational order of the machine, each of which is provided with a laterally extending lug i139 adapted; upon depression 'of control key lfandconsequent counter-'clockwise rotation of rock shaft ll' through lever 95 and pawl to engage lug lll of hook members e8.

The parts are maintained in such locking engagement during subsequent depression'of ordinal keys `representing gures of the subt'rahend which, previously explainedg'vv'ould normally result in' a power action through engagementof hook' with toothed wheel 13,'and until released hy depreSsiOnof'the equals'key y8".

The digital actuation of the ad'dingmecha'nism is automatically controlled in a'ccordancey with the nines complemental value of the keys depressed in'ent'erihg a subtrahend in all 'deno'rnif national orders except the units order, in which the tens complemental `value ofithe key de pressed is added. The mechanism vcontrolling the digital actuation or the adding mechanism in each denominational order is indicated `aenerally at @l (Fig. 6) and comprises a regular stop bar i12 Aand a complemental stop har H3, secured togetherand spaced relative to each other by means otstuds i (Figs. 5 and 8). The bars i12 and H11 have formed-thereon vertically projecting stoplugsvllli, the lugs H5 of the stop barl HZbeing spaced progressively furtherback "of the. key-stems. from thofrontftoitne-irear ofthe machine, and the lugs'l I5 of stop'bar -lfl'beliig 4spaced progressively further back A of Vtliekey vstems `from the rear to the -front oftheniacnine (as shown inFigs. 3, 5, 6 and 8). The stoplug H5 of the regular stop bar H2 just t'o the/rear stop lug is just even withthe "9 key.

It has been'earlierexplained thatin machines of this type ithas been the necessary prac'tlc in "enter-ing the subtrahend to enter one less'n the unitsorder or, inother words, to strikethe nines complement of all orders except the units y order,

lin which the tens complement was enteredfto obtain the correct result. The means`for`-`con trolling the digitalA actuation of the accumulator mechanism in the units order naccordance `with thfe ten@ Complement 0f the key depressedor.'i`f

no-keyhas beenl depressed,'to automaticall'yfadd "10 in such order tcbring about the correo re;- sult, is accomplished by an arrangemeiitors'pacf ing of the vstops on `the tens c omplemental'stp bar H3' of the units order" as shown in F i"gf."7. differentY from; that of 'the nines' complemental stop bar H3 in all other orders. InA 'other words :the stops l.|5on the tensc'omplemeiital stop'bar H3 of the movement controlling bar 6l in 'the units order (Figs: jand '7) are spaced .progressively one step further back than 'are the 'stopfs on theV nines complemental stop"ba'rs' |113). The gear's'ectorin the units order tlirefore'fis given a relatively greater adding movement by the tens 'complemental' stop bar lf3" than; are Ythe gear sectors of all other higher denominati. "tional orders 'under 'the control of their comple; mental stopbars H3. 'Tliecom'plemental/'stop bars H3' and H3' arep'rovided vat their forward ends with vdepending karms ne having a' 'Bifurcat'ed portion adapted to' embrace the-pin located in 'the' upwardly extending arm '3a-"of the associated'l gear sector `42 (Fig. 3'). c Means are' provided, whendesiring tojenterthe complementof the subtrahend during asubtrac; tive operationLforshifting the complemental-stop bars l i3 and v|13 into operativerelation withythe ordinal series 'of keys, so that upon depression orma key andsubsequent downwardV movement of the gearcsector 4 2, the complementari value. of the key depressed will be added into the accumulater, as distinguished from, the actual value of the key depressed when, the regular stop har.` Hf-Z is in operativerelationtherewith.y The lower'porh tion of stem 8 8 of the subtraction control minus key 86 is provided with an angular surfacev in engagement with a roll H8 which isrotatably secured to an upright arm H9 (viewing Fig`.3), which in turn is-xedlysecured toa longitudinal rock shaft I2! having a bearing in vertical-'support pieces H1 and H1 which are supportedon` tie-'rods 23; Also securely fixed to 'the rockshaft l2| are upright arms |23 and T24, located at the front and rear of themachine, 'respectivelygf (Fig. 3). YThe upper free portion of' the arm: l z34 is oisposeduna smanfsiotted portion lzf'u loff-"a transverse"supportA bar |25 positioned'ne' 'the zontal arm provided at its forward end with a small slotted portion |20 in which is positioned the upper portion of the upright arm |24. The bar |21 is also provided with pins |26 adapted to be embraced by the open portion of the digital control bars 6| to maintain proper alignment of the rear ends thereof with respect to the key stems 41. The rock shaft |2| and the support bars and |21 and digital control bars 6| are normally maintained in the position of Fig. 9 under tension of a spring |38 (see Fig. 3) interconnected between thelower end of the arm |23 and a frame plate 22 to retain the regular stop bars ||2 in operative relationship with their associated digital key stems.

With such an arrangement, it will be readily perceived that upon depression of the minus control key 86, the resulting movement of arm ||9 to the right (viewing Fig. 11) will cause the shaft |2| to be rocked counter-clockwise to shift the support bars |25 and |21 to the left (as seen in Figs. 9 and 10), through the medium of upright arms |23 and |24. The digital control support bars |25 and |21, will similarly be shifted toposition the stop bars I3 and I3 in operative relationship with the stop portions |9 of the key stems 41. When either of the stop bars H2 or H3 is in operative relation with the stop portion I9 of the ordinal key stern, the other stop bar is completely out of operative relation therewith. A slot 40 is cut in the lower portion of each of the key stems 41 and is adapted to be in alignment with the stop bars |3 and |3' when the stop bars I2 are in effective or operative position relative to the key stems 41, as shown in Fig. 9. When the stop bars ||3 and ||3 are in effective or opera-Y tive position relative to the key stems 41, then the stop bars 2 will pass freely by the stop portions |9 at the left of the key stems, as viewed in Fig. 10.

The means for releasing the clutch hooks 58, after the subtrahend has been set up on the keyboard, is under the control of the equals key 81, the stem 88 of which is in engagement with a lever |28, see Fig. 4. Depression of key 81 and lever |28 causes clockwise rotation of pawl 98 disengaging its lower arm 99 from pin |95 of the arm |06 and allowing the shaft |01 to be rocked clockwise under the tension of its spring |80, see Fig. 3. The lock arms |08 are thus removed from locking engagement with lugs on hooks 58, thereby allowing those hooks in the denominational orders in which digital keys have been depressed in the previous setting of the subtrahend into the keyboard to drop into engagement with their toothed wheels 13.

As has been mentioned, it is necessary that 9s" be added in all denominational orders other than the units order, in which no digital key has been depressed, and that 10 be added in the units order if no key has been depressed therein, for the purpose already explained. The lever |28 pivoted on a short shaft |3| is provided with an arm |34, the lower bifurcated end |35 of which embraces a pin |36 fixed in the upper. end of an arm |31 which is securely fixed to a transverse rock shaft |38'. Also securely fixed to the rock shaft |38 are upright arms |39, one for each denominational order, the upper extremities of which are in engageable relationship with pins |4| in links 55 (Fig. 2). Depression of equals key 81 through lever |28 and arm |31 causes forward rocking movement of shaft |38 and arms |39, thereby urging links 55 forwardly. The forward movement of the links 55, through the parallel motion device, causes depression of hooks 58 controlled thereby into the paths of their associated toothed wheels. Movement of the parallel motion device not having resulted from depression of a digital key 24 in such order, the bar 6| which controls the digital setting of the sector gear 42 will receive full forward movement, with a consequent maximum downward y movement of the gear sector suiiicient to add 9 into the accumulator upon the upstroke of the sector under tension of spring 46. When no key has been depressed in the units order, that is, when z a zero occurs in the units order of the subtrahend,

forward swinging of the arm |39 therein will likewise cause maximum downward movement of the gear sector 42, but the resultant upstroke by the spring 46 will add 10 into the units order of the accumulator.

To automatically add 9 to the accumulator mechanism of the overflow order to bring to zero position the numeral wheel of that order when a 1 has been carried thereto by the entering of the complemental value of the subtrahend and the subsequent adding of 9s and carrying of the l across the register as just described, a sector 242 is provided, see Fig. 4. The sector 242 is similar to the sectors 42 already described and mounted on the shaft 43, but is directly connected to guide member 260 by link 259, and rearward movement of guide member 269 to move sector 242 downwardly is accomplished through connection with guide member 69 of the next lower denominational order. This connection is effected by depression of minus control key 86 and forward movement of link 255 which, through i' pin |46 fixed in link 255, causesrocking movement of lever I 48 and engagement of lock piece |54 with pin |51 fixed in the guide arm 60. The lock piece |54 is mounted on the guide arm 260, and when hook member 58 engages with toothed wheel 13 of the denominational order to the right of the overflow order, resulting either from setting of a digital key 24 therein and/or depression of the equals key, the guide member 60 in that Order will be pulled rearwardly and, by its connection with guide member 269 of the overflow order, the gear sector 242 of the overiiow order will be given a maximum downward movement to add 9 upon its upward movement under the action of spring 246.

As the guide member 260 is moved rearwardly as just described the pin 211 located thereon engages and releases the latch 266 from the dog 261 to allow the parallel motion bar 89 to return to its normal raised position and allowing the key 86 to be raised to its normal elevated position.

Means are provided for preventing the relatching in a depressed position of parallel motion bar 89 and minus key 86 if the equals key 81 is allowed to rise while key 86 is still being held depressed by the operator, or if the equals key 81 is held down by the operator. To this end, there is provided a forwardly extending arm |59 on latch 266 of the overflow order which is adapted to engage the face of a lip or lug |6| formed at the extremity of a vertical lever |62 amamos 111 (as shown in Figa). The lever |62 is moved;-k slightly' clockwise 'against 'the tension 'of' its spring i631' by'the arm 159 when-parallelmotion bar SB'is depressed bythe .min'us key 86; and'` to the rear' of projection 216 of `dog"261, and the' dog -"cannot be' relatched' in "su'ch` po"sition untill the parallel motion" bar '89" has 'be'en""allowed to' return'to its upper"or'noriral'position'arid'has again "been 'depressed by 'the`"minus` key` 86; Thus' the' -subtmctive 'control devices' are corni pelled'to "return to'normalpo'sition after'a subtractive "operation, and f.the machine" is" auto?" matic'ally "conditioned 'for' additive' operation."

All of themstructure thus fai" described is described,"illustrated,an'd clairne'd'in `my 'copending application Serial" Number' 411,19L' hereinabove 'referred 'tol The present invention is'more particularly con# y cern'edwith the' provision" in such a machine of simp'lie'd means' for performing division." HereVA tofor'e, in machines "of thetype disclosed, division. 35'

was 'performed by a process"of'repeated'addition"' of the'v complement of the value of the diviso'rlV For instance', 'ifv it werev desired "that'the' figure' 11,856 be divided by ine figure H456?J ine for:y

the inscription onthe keys ofthe nin'es'co'inpla pn.

ment of the value vthereof in 'small g'u're'sKsee FigflA); it being 'necessary' 'to V'hold th'jfin'g'e'r tips inco'ntact'with the key tops'of the digit'ke'ys' representing the value of'the divisor, lessone' in' the lowest 'signicant order4 of "'the'- divisor, on,

the small complemental 'gu'resof the-keys? The" ment of the divisor, 'were' 'then' repeatedly delN pressed until th'e'numeral'wheel'in they order next higher than 4the highesthorder of the divisor "60 showed 'a value equal dto' the' number' of V`op'i'e'ratio'ns"l er depressions; nine remainder in the orders inte which 'the' complement' 'of th'e 'divisor was being" entered was greater than thedivisonthe repeated depressions were' 'continued until' th'e'f remainder 654i was less than the"v divisor` 'after'whioh the divisor was shifted one order to the right' andv the' process" was repeated'. By"th'is processAv the quotient 26 is re'g'ist'eredin 'the-numral'wheels ofthe' z'iccuL 4 70 Howeverjwli'ere'the divisor' containedth'e' figi'r'e mulat'o'r' with" no remainder."

9 inf'tne units erderij'or in the' intermediate 1n 'this' pe'sitio'n.,- trie'j downwardly e'xte'ndir'igv arm' '2150i the latch 266 is tween-1 two guresof value;-fcertainrulesfhadl tobe 'followed Yfinorder to obtainthe correct result;` For instancefif va"9 occurredasthe highest denominationaliigure ofthe divisor or asan intermediate iigure between r`two figures of value,-

it wasigno'red andi-1o key wasY depressed in that* order in which the 9N appeared.- If, however,

the 9r voccurred' as the units iigure ofthe divisor,

the same rule' aseearlier explained was-followed" and lone` less, or the small figure 3 was'de pressed Also, where a( cipher or ciphers-occurred as an intermediate ngure of therdivisor between two figures of value, the small'ciphcr wasde-y pressed, but where thecipher for Ciphersi oc-l curred inorders lower' than--the-flowest signifi-- cantfiiglleofI the divisor they -were ignoredY and-1 no l': eyi vas`- depressed in' those orders. The above rules`fornulated to meet certain conditions have been vsource of much confusion to the operator and asa result-inmaohi'nes of the type disclosed;

the 'performance `offnegative calculation,l such as subtraction and division, has not fbeenwas facile as'desire'd.

In the' present invention, however, the operator is completely' relieved of the responsibility and mental burden of determining the complement f nines'complement' of -any key subsequently depressed in any' denominational orderfhigherY than the units' 'orden' andltoautomatically `add the te'ns v'complement of the -key depressed-in the-- units"order,"and' to add' 'the respectivey complements of zero' in 'all orders' to the right of the leftmost or'highest order of the divisor where no keys are' depressed, except theunits order, in-y which lO is added if no' key is'depressed therein-.-= For division operations, 'the complementalmark-ling of' thev keys 'is' dispensed with, soV there are A only the large' figures thereon. Itrwill be-under;

. stood` that vit is no longer necessary to'hold one less tha-n the lowest significant figure of the divisor'whichhas heretofore been-necessary ir1y performing division on Ythis type Yof machine.'4

This .is vaccomplished byautomatically `adding S'Tsnnallorders to the right of the `lowest-'sig*` nificant gure of the divisor except the unitsy order'in-which 10'isv added -to cause a carry to take'Y place-to add \1 in thede'non'iinational'A orde-r in which the lowest signicant digit of the 1 divisorfis bein-g depressed;

Fur-ther, as `will-bey presently'explainedfithel -f rules heretofore mentioned in connection-With the performance ofdivision when the iigiire9' oc'" curred 11i-.the yunits order or intermediate order/ or' orders-`of thefdivisorbetween-"two figres' of` valuefandiwhe're a cipher ("05 occurred ini an -1 intermediate order ororders'of the' divisor, have i' been completely eliminated? In vpe'rio'iiningA divi' sion" onf-the machine' of `thepresen't' -invention,`

Where the figure 9 occurs in the divisor, the* 9 key"is"depre's'se`d," and 'where'a cipher (0) occurs',"'initlicatinga lack 'of values, no key'isde-v press'edj Division-'is accomplished," therefore;

'Without-'thefcomplernental markingof'the keys" and without triene'eessity ef holding one less' in the lowest'sign'icant order 'of the divisor,"and

Witlio't th necessity of reference to' or' a knowl` edge'oi thel'rulesfhereteiorementioned, in the two preceding paragraphsg'allof which have here' tofore been a source of much confusion to the operator.

To perform division on the machine in which the present invention is embodied, it is rst necessary to enter the dividend into the register wheels of the accumulator by depression of the keys in the usual manner. The present invention is more particularly concerned with the provision of means for facilitating the performance of division by conditioning the machine to automatically control the digital actuation of the actuating mechanism therein in accordance with the complemental value of the keys depressed in entering the divisor. Such means completely eliminatethe heretofore dual marking of the keys in accordance with the nines complemental Value thereof, thus relieving the operator of the mental burden connected with determining' the complementa] value of the divisor. In the exemplary' embodiment, after the machine is conditioned for division by depression of a division control key, subsequent to the entering of the dividend, the keys representing the gures of the divisor are repeatedly and simultaneously depressed in accordance With the rules heretofore mentioned. However, in accordance with the present invention, it is no longer necessary to hold one figure less than the actual value of the units figure of the divisor which has heretofore been necessary. The addition of the extra l in the units order of the divisor as it is depressed in the varying lower denominational orders in performing division is automatically provided for and the keys representing the actual fguresof the divisor are simultaneously depressed.

The means for controlling the operation of the machine in division consists of a division control key 3|l| which is located to the left of the ordinal series of keys 21| (Fig. 1) below the subtraction control keys 8E, 81. The key 39| is provided with stem 88 and spring 38 to normally maintain it in raised position. The stem 88 of the key 30| is provided with an angular lower portion 3D2 in engagement with a roll 303 which is rotatably secured to an upright arm IIS (viewing Figs. 3, 9 and 10). The arm IIS' is rotatably mounted on the rock shaft |2I which, when rocked as earlier described herein, causes the complemental stop bars ||3 and II3' to be shifted into operative relationship with the key.

stems 41 to control the digital actuation of the actuating mechanism in accordance with the complemental value of any key subsequently de-I pressed. Rigidly mounted on the rock shaft |2I is an arm 3M, the upper extremity of which is in engagement with a pin 385 fixed in the arm IS'. From said construction it will be readily understood that the rock shaft I2I may be rocked in a counter-clockwise direction, viewing Figs. 9 and 10, to shift the stop bars ||3 and II3 to the leftY when the minus control key 86 is depressed, Without effecting movement of the arm I I3 which is normally maintained in the position of Fig. 9 under tension of a spring 30B. i

The arm H9 is provided with a lower downwardly extending portion 391 which terminates in a vertical bifurcated end 398 embracing a groove 309 formed in a transverse shaft 3| I (Figs. 9 and 10). The shaft 3| is journaled for lateral movement in bearings 3 I2 fixed in the outer frame plates of the machine, and is adapted to be moved to the right against the tension of spring 306 upon depression of the division control key 39| which,

through medium of arm 304 and pin 385, also rocks the shaft 2| to move the complemental 14 stop bars I I3 and I 3' into operative relationship with the keys 24.

Mounted on a transordinal shaft 3|3 which is disposed in parallel relationship with the shaft 3I| are actuation levers 3|4 which are provided between adjacent denominational orders (see Figs. 2, 3, 9, 10 and 12). The levers 3|4 are provided with vertical arms 3|5 and 3I6 which are joined together by a transverse bail portion 3I'|, the arm 3|6 being slightly offset to the right, viewing Fig. 12, so as to be aligned with the arm 3|5 of the lever 3 I4 of the next lower denominational order for a purpose to be presently explained. The levers 3 I4 are normally maintained in the lateral position of Figs. 9 and 12 under the tension of spring 305 which as earlier explained, is connected at one end to the arm I9' which is in communication with the laterally movable shaft 3| I through the downwardly extending portion 301 and bifurcated end 308. Clinched to the shaft 3| are shifting arms 322 which are provided with bifurcated rearward portions 323 adapted to embrace the shaft 3I3. An arm 322 is provided between each two levers 3M and also on the outside to the left and right of the set of levers 3|4 adjacent the arms 3|5 and 3|6, respectively. In the position of Figs. 9 and 12 the upper extremities of the arms 3 I 5 and 3 I 6 are out of the plane of movement of the pin |4| of the link 55. In such position the levers 3M are prevented from rotative movement on the shaft 3I3 by means of a pin 3 I 8 fixed in the intermediate frame plate 22 which is adapted to enter an aperture 3| 9 in the extremity of a horizontal rearward extension 32| (see Fig. 3) formed on the lower end of the vertical arm 3| 5.

When the shaft 3| I is shifted, to the right viewing Figs. 9 and 10, by depression of division control key 30|, the shifting arms 322 which are clinched to the shaft 3| I move with it to cause lateral sliding movement of the levers 3I4 into the plane of movement of and engaging relationship with the pins I4| in the links 55. In the position of Fig. 10 it will be noted that the aperture 3I9 in the horizontal extension 32| on the arm 3|5 has been freed from engagement with the pin 3|8 fixed in the intermediate frame plate 22 and the lever 3M is then free for rotational movement on the shaft 3| 3 as will 'presently be described. In such position it will be noted that the arm 3|5 is forward of the pin |4| while its associated arm 3|6 is rearward of the pin I4| of the next lower denominational order, to the left viewing Fig. 10. With such an arrangement it will be readily apparent that the forward action given to a link 55 by depression of a key will cause, through the pin |4| and arm 3|5, clockwise rotation (viewing Fig. 12) of the lever 3M. Through the associated arm 3|6, forward movement is transmitted to the link 55 of the next lower denominational order which movement imparts motion to the associated parallel motion bar to cause depression of the hook 58 controlled thereby into the path of its associated toothed wheel 13, which results in an adding actuation in thatv 6I which controlsthe digital setting of the'gearl Y sector 42 will receive full forward movement, with arcanos a consequent maximum downward movement of the gear sector suicient to add 9 into the accumulator upon the upstroke of the sector under tension of spring 46. In the units order also, the gear sector 42 will receive lmaximum downward movement, but the resultant upstroke by the spring 45 will add 10" into the units order of the accumulator. Adding of in the units order causes a carry of 'the tens to take place in every order in which 9 has been automatically added to the right of the lowest order of the divisor until finally the l is carried into the order in which the units figure of the rdivisor has been added.. Thus depressing of keys corresponding to one less than the actual value of the divisor vwhen the keys are simultaneously depressed in performing division on the instant type of machine has been made unnecessary.

To `insure full forward movement of the links 55 despite the cumulatively increasing strain upon the ordinal elements of the series of overlapping actuation levers 314, there is provided in association with each yielding clutch 63 a cam portion 325 (Figs. 2 and 3) formed integrally with the center disk of the yielding clutch 63. As earlier mentioned, the link 59 is articulately connected to the yielding clutch 63 through this center disk. When an ordinal key 24 is depressed the link 55 is moved forwardly as earlier described to permit engagement of the hook 58 with toothed wheel 13 which causes rearward movementv of the link 59. As the link 59 is moved rearwardly, the center disk of the yielding clutch B3 to which it is connected is rotated in a clockwise direction, viewing Fig. 2, and the cam portion 325 engages a roll 325 mounted on pivot or stud 56, to which the forward end of link 55 is connected to postively force forward movement of the link 55 and remove any strain attendant with the function of the overlapping actuation levers 314 as earlier described.

Due to the slightly delayed Vreturn of the link 55 because of the engagement of the cam 325 with the roll 326, the return of the key under fast operation is also vsomewhat slower so means are provided to prevent re-engagement of latch 65 and dog 51 after disengagement by the pin 11 as earlier described. To this end there are provided latches 321 (Figs. 2, 13, and 14) each having huh portions 328 and being mounted on a transverse shaft 329. Each latch 321 is provided with an upwardly and rearwardly extending portion 33t and terminates in a horizontal arm 332 which is adapted to underlie the pin 11 on the guide arm 63 and be resilientlymaintained in engagement therewith by means of a spring 333. As a key 24 is depressed and the link 55 moves forwardly, the latch 69 carried by the link 55 also moves forwardly disposing the finger 19 above the arm 332 of the latch 321. As the clutch hook 58 engages with the toothed wheel 13 and the link 59 and guide arm 60 move rearwardly the pin 11 mounted in the arm 13 engages the finger 19 to release the latch 66 from the dog 61. As the pin 11 moves rearwardly in an arc, the horizontal arm 332 is allowed to rise under tension of spring 333 when the nger 19 is moved rearwardly from engagement with the extremity of the horizontal arm 332. When the guide arm 6D and link 59 move forwardly under the tension of spring 45 after release of the clutch hook from the toothed wheel, the pin 11 is removed from engagement with the finger 19 which is allowed to rotate in a counterclookwise direction under tension of spring 64 but which contacts the endv of the arm 332 and is maintained in released position relative to the dog 91 until the guide arm 59 and link 59 have reached full forward position. As the guide arm is being rotated clockwise about its pivot 59 under tension of spring 46 the pin 11 strikes the upper surface of the arm 332 and cams it downward out of engagement with the finger 19 and the latch 66 is allowed to be rotated to its normal position of Fig. 2. However, as previously explained, the shelf 1I of lever 12 strikes lug 59 of dog t1 to hold the dog out of engageable relationship with latch 65 after lsaid latch has returned to its normal position so that no re-engagement of the latch and dog is possible if the digit key is prolongedly held in depressed position. Without the latches 321, the latches 55 would re-engage with dogs 61 after every key stroke, to be released only by the forward motion of the lugs 15 to the dogs 61 out of engagement with the arm 15 of the latch 66 when the dogs 61 are swung counter-clockwise by shelves 1l of levers 12, which would make the rising of the keys too slow for fast operation of the machine.

As has been described, upon depression of the keys representing figures of the divisor when performing division, 9s are automatically added in all denominational orders where no keys are depressed to the right of the left-most order in which a key is depressed. In such automatic actuation of the orders to the right, resistance to forward movement of the link 55 by actuation levers 314 is present in the springs 64 and 334 of the denominational orders to the right of the key operated order and it may be possible that the link 55 may be moved forwardly enough to cause latching engagement between latch 66 and dog 61 but not sufficient to result in engagement between the clutch hook 58 and toothed wheel 13. Means are provided, therefore, for1 releasing the dog 61 from the latch 53 in any orders in which such a condition exists by operation of the zeroizing crank 335 or depression cf a release key 311.

Mounted -on a stud 335 xed in the intermediate frame plate 22 toward the rear of the machine is an arm 331, having a pin 338 fixed in the lower portion thereof (Fig. 19). A lever 339 is mounted on the pin 338 and extends forwardly and downwardly terminating in a hook 341 in engagement with a notch 342 (Fig. 19) cut in a transordinal shaft 343. At the right hand side of the machine, viewing Fig. l, an arm 344 (Fig. 15) is rigidly mounted on the shaft 343 and has pivotally sef cured to its upper extremity a link 345 which is provided with a slot 345 at its forward end. Disposed within the slot 346 is a stud 341 which is mounted in the intermediate portion of a depending lever 348 (Fig. 15) which is part of the zeroi-zing mechanism and adapted to be rotated in a counter-clockwise direction about its pivot 349 when the zeroizing crank 335 is pulled forwardly, or to the right viewing Fig. l5. As the zeroizing crank 335 is pulled forwardly the notched shaft 343 is rotated in a clockwise direction against the `75353, through its engagement with the pin 352, 

